- Synthesis of benzofuran derivatives using manganese (III) acetate mediated addition of β-dicarbonyl compounds to alkyne and alkenes - A comparative study
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β-Dicarbonyl compounds were easily oxidized with manganese (III) acetate in acetic acid to form the corresponding α-carboradicals, which attacked alkyne and alkenes to give furan derivatives in good yield.
- Yilmaz,Pekel
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- Rh(II)-mediated one-pot synthesis of dihydrobenzofuran and spiro[2.5]oct-1-ene: Experimental and DFT studies
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This study represents an experimental and computational approach to investigate the rhodium-catalyzed one-pot synthesis of dihydrobenzofuran-4-one (DBF) and spiro[2.5]oct-1-ene (SOE) derivatives. Density functional theory (DFT) calculations were performed at B3LYP and M06-2X level theory. For mechanistic studies, the calculation employing B3LYP/GenECP/LanL2DZ/6-311++G(d,p) level of theory demonstrated that a [3 + 2] cycloaddition reaction between diazo compound and phenylacetylene (PhA) proceeds through a two-step mechanism via a barrierless and highly exergonic process with relative free energy 73.61 kcal/mol to yield the kinetically favored DBF derivatives (50%–62.5%). In contrast, the assemble of SOE derivatives follows [2 + 1] cycloaddition between in situ generated cyclohexane-1,3-dione carbene-2 and PhA, with the potential energy barrier 4.41 kJ/mol. Thermochemistry calculation disclosed that the cycloaddition reactions are spontaneous, and DBF (6a) is thermodynamically more stable than its constitutional isomer SOE (7a) by 42.59 kcal/mol. However, natural bond orbital (NBO), HOMO–LUMO energy gaps (4.62–4.89 eV), dipole moments, polarizability, first-order hyperpolarizability, and global reactivity descriptors were calculated to understand products' structural features. Additionally, Merck Molecular Force Field (MMFF94), followed by the B3LYP level of theory, was applied to predict the relative stability for the various conformations of 6b and 7b. The Boltzmann weighted average 1H chemical shift computed by GIAO-B3LYP/6-311+(2d,p) method and UV-Vis absorption calculated using time-dependent density functional theory (TD-DFT) agree with experimental results. Finally, the synthesis of DBF and SOE derivatives is herein illustrated.
- Hoque, Mohammad Mazharol,Bari, Md. Abdul,Khan, Md. Wahab
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- Nucleus-independent chemical shift (NICS) as a criterion for the design of new antifungal benzofuranones
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The assertion made by Wu et al. that aromaticity may have considerable implications for molecular design motivated us to use nucleus-independent chemical shifts (NICS) as an aromaticity criterion to evaluate the antifungal activity of two series of indol-4-ones. A linear regression analysis of NICS and antifungal activity showed that both tested variables were significantly related (p –1 for Candida glabrata, Candida krusei and Candida guilliermondii with compounds 15-32, 15-15 and 15-1. The MIC for filamentous fungi was 1.95 μg·mL–1 for Aspergillus niger for compounds 15-1, 15-33 and 15-34. The results obtained support the use of NICS in the molecular design of compounds with antifungal activity.
- González-Chávez, Marco Martín,González-Chávez, Rodolfo,Méndez, Francisco,Martínez, Roberto,Ni?o-Moreno, Perla Del Carmen,Ojeda-Fuentes, Luis Enrique,Richaud, Arlette,Zerme?o-Macías, María de los ángeles
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- Synthesis of oxazole and furan derivatives via Rh2(OAc)4-catalyzed C≡X bond insertion of cyclic 2-diazo-1,3-diketones with nitriles and arylacetylenes
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A convenient and efficient procedure for the synthesis of 2-substituted-6,7-dihydrobenzo[d]oxazol-4(5H)-ones and 2-aryl-6,7-dihydrobenzofuran-4(5H)-ones through a Rh2(OAc)4-catalyzed C≡X (X = N, C) insertion of cyclic 2-diazo-1,3-diketones with nitriles and aromatic alkynes has been developed. This reaction uses readily available starting materials and stable cyclic 2-diazo-1,3-diketone compounds, with desired products formed in good to high yields. A tentative mechanism involving a C≡X bond insertion and 1,5-dipolar electrocyclization/ring opening and cyclization sequence for this reaction is proposed.
- Fan, Chenli,He, Xinwei,Zuo, Yin,Shang, Yongjia
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supporting information
p. 2782 - 2792
(2018/11/06)
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- Rhodium(III)-Catalyzed Regioselective Decarboxylative Cyclization for the Synthesis of 4H-Furo[3,2-c]chromen-4-one Derivatives
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This contribution describes a regioselective cyclization of hypervalent iodine reagents (HIR) with propiolic acids in the presence of a rhodium catalyst. The mild decarboxylation can tolerate a wide range of groups and generates 4H-furo[3,2-c]chromen-4-one derivatives in good isolated yields. (Figure presented.).
- Zha, Dandan,Li, Hongji,Li, Shiqing,Wang, Lei
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p. 467 - 475
(2017/02/10)
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- Regioselective synthesis of highly functionalized furans through the RuII-catalyzed [3+2] cycloaddition of diazodicarbonyl compounds
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A novel method for the RuII-catalyzed regioselective synthesis of highly functionalized furans from readily available cyclic and acyclic diazodicarbonyl compounds and terminal alkynes is described. The devised protocol offers a straightforward means to the construction of a variety of diverse furan derivatives through powerful cascade processes, including the formation of ruthenium carbenoid, cyclopropenation, ring-opening metathesis, and cyclization. Copyright
- Xia, Likai,Lee, Yong Rok
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p. 3430 - 3442
(2014/06/09)
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- Pd(II)-catalyzed sequential C-C/C-O bond formations: A new strategy to construct trisubstituted furans
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Palladium-catalyzed oxidative difunctionalization of enol ethers with 1,3-dicarbonyl compounds to construct trisubstituted furans in one step under mild conditions is described. The reaction is thought to proceed through a C-C bond formation along with a C-O bond closing the ring structure. Oxygen is the sole oxidant regenerating the Pd(II) catalyst.
- Zheng, Meifang,Huang, Liangbin,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 1838 - 1841
(2013/06/04)
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- One-pot synthesis of furans using base- and acid-supported reagents Na 2CO3/Al2O3-PPA/SiO2'
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A convenient method for the one-pot synthesis of furans from -keto esters and -halo ketones was developed using an acid- and base-supported reagent system Na2CO3/Al2O3-PPA/SiO2'. The condensation reaction of triketones, which are formed from the reaction of -keto esters with -halo ketones in the presence of Na2CO 3/Al2O3, was promoted by PPA/SiO2 to give the corresponding furans in good yields. This method is simple and easy to perform in comparison with stepwise processes, and the yields are good.
- Aoyama, Tadashi,Nagaoka, Takashi,Takido, Toshio,Kodomari, Mitsuo
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experimental part
p. 619 - 625
(2011/04/15)
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- Oxidative addition of 1,3-dicarbonyl compounds to terminal acetylenes mediated by cerium(IV) ammonium nitrate
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Cerium(IV) ammonium nitrate mediated oxidative addition of 1,3-dicarbonyl compounds to terminal acetylenes to yield multisubstituted furan derivatives is reported here. The simplicity of the reaction and the ease of execution are particularly noteworthy.
- Sivan, Akhil,Deepthi, Ani,Nandialath, Vidya
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experimental part
p. 2466 - 2470
(2011/09/19)
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- [3+2]-Cycloaddition reactions of 2-phenyliodonio-5,5-dimethyl-1,3-dioxacyclohexanemethylide
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Iodonium ylide 2, derived from dimedone, undergoes thermal [3+2]-cycloaddition with acetylenes and nitriles with Rh2(OAc)4 to form the corresponding furans and oxazoles, respectively. Photochemically 2 reacts with various alkenes to
- Gogonas,Hadjiarapoglou
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p. 9299 - 9303
(2007/10/03)
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- Photochemical Reaction of Phenyliodonium Ylides of β-Dicarbonyl Compounds with Terminal Alkynes
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The photochemical reaction of phenyliodonium ylides of acyclic β-dicarbonyl compounds bearing at least one benzoyl group with terminal alkynes leads to the formation of 4-substituted-2-acyl-1-naphthol derivatives, probably through iodanes and ethynylated
- Kalogiannis, Stavros,Spyroudis, Spyros
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p. 5041 - 5044
(2007/10/02)
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- Carbenoid Type Reactions of a Stabilized Bismuthonium Ylide in the Presence of Copper Catalyst
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Triphenylbismuthonio-4,4-dimethyl-2,6-dioxocyclohexan-1-ide reacts with 1-alkynes in the presence of small amounts of copper(I) chloride to form bicyclic furan derivatives probably via a carbenoid intermediate.
- Ogawa, Takuji,Murafuji, Toshihiro,Iwata, Kazuhiko,Suzuki, Hitomi
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p. 325 - 328
(2007/10/02)
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- DIRECT SYNTHESIS OF FURANS BY 3 + 2 CYCLOADDITIONS BETWEEN RHODIUM(II) ACETATE STABILIZED CARBENOIDS AND ACETYLENES
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When appropriate substituents are used, rhodium(II) acetate catalyzed decomposition of diazocarbonyls in the presence of acetylenes results in the formation of furans, derived from dipolar intermediates.
- Davies, Huw M. L.,Romines, Karen R.
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p. 3343 - 3348
(2007/10/02)
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- Regioselective Synthesis of Dihydrofurans from 2,2-Dibromo 1,3-Diones and Olefins Using Copper
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2,2-Dibromo 1,3-diones reacted with copper powder and olefin to give 2,3-dihydrofuran derivatives in a highly regioselective fashion.Acetylenes and 1,3-dienes also reacted with 2,2-dibromo 1,3-diones and copper to afford furan derivatives and 2-vinyl-2,3-
- Yoshida, Jun-ichi,Yano, Shinji,Ozawa, Tadahiro,Kawobata, Nariyoshi
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p. 3467 - 3473
(2007/10/02)
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- REGIOSELECTIVE SYNTHESIS OF DIHYDROFURANS FROM 2,2-DIBROMO-1,3-DIKETONE AND OLEFIN USING COPPER
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2,2-Dibromo-1,3-diketones reacted with copper powder and olefin to give 4,5-dihydrofuran derivatives in a highly regioselective fashion.
- Yoshida, Jun-ichi,Yano, Shinji,Ozawa, Tadahiro,Kawabata, Nariyoshi
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p. 2817 - 2820
(2007/10/02)
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- Synthesis and Mass Spectrometry of 4-Oxo-4,5,6,7-tetrahydroindole and 4-Oxo-4,5,6,7-tetrahydrobenzofuran Derivatives
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We describe in this communication the synthesis and mass spectrometry of some 1-aryl-2-phenyl-4-oxo-4,5,6,7-tetrahydroindole (IIIb, IVab-VIIab,VIIIb, IXb) and 2-phenyl-4-oxo-4,5,6,7-tetrahydrobenzofuran derivatives (IIab).The fragmentations of these compo
- Dagher, C.,Hanna, R.,Terentiev, P. B.,Boundel, Y. G.,Kost, A. N.,Maksimov, B. I.
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p. 645 - 647
(2007/10/02)
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